chrome/common/extensions/message_bundle.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_COMMON_EXTENSIONS_MESSAGE_BUNDLE_H_
   6 #define CHROME_COMMON_EXTENSIONS_MESSAGE_BUNDLE_H_
   7
   8 #include <map>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/memory/linked_ptr.h"
  13
  14 namespace base {
  15 class DictionaryValue;
  16 }
  17
  18 namespace extensions {
  19
  20 // Contains localized extension messages for one locale. Any messages that the
  21 // locale does not provide are pulled from the default locale.
  22 class MessageBundle {
  23  public:
  24   typedef std::map<std::string, std::string> SubstitutionMap;
  25   typedef std::vector<linked_ptr<base::DictionaryValue> > CatalogVector;
  26
  27   // JSON keys of interest for messages file.
  28   static const char* kContentKey;
  29   static const char* kMessageKey;
  30   static const char* kPlaceholdersKey;
  31
  32   // Begin/end markers for placeholders and messages
  33   static const char* kPlaceholderBegin;
  34   static const char* kPlaceholderEnd;
  35   static const char* kMessageBegin;
  36   static const char* kMessageEnd;
  37
  38   // Reserved message names in the dictionary.
  39   // Update i18n documentation when adding new reserved value.
  40   static const char* kUILocaleKey;
  41   // See http://code.google.com/apis/gadgets/docs/i18n.html#BIDI for
  42   // description.
  43   // TODO(cira): point to chrome docs once they are out.
  44   static const char* kBidiDirectionKey;
  45   static const char* kBidiReversedDirectionKey;
  46   static const char* kBidiStartEdgeKey;
  47   static const char* kBidiEndEdgeKey;
  48   // Extension id gets added in the
  49   // browser/renderer_host/resource_message_filter.cc to enable message
  50   // replacement for non-localized extensions.
  51   static const char* kExtensionIdKey;
  52
  53   // Values for some of the reserved messages.
  54   static const char* kBidiLeftEdgeValue;
  55   static const char* kBidiRightEdgeValue;
  56
  57   // Creates MessageBundle or returns NULL if there was an error. Expects
  58   // locale_catalogs to be sorted from more specific to less specific, with
  59   // default catalog at the end.
  60   static MessageBundle* Create(const CatalogVector& locale_catalogs,
  61                                std::string* error);
  62
  63   // Get message from the catalog with given key.
  64   // Returned message has all of the internal placeholders resolved to their
  65   // value (content).
  66   // Returns empty string if it can't find a message.
  67   // We don't use simple GetMessage name, since there is a global
  68   // #define GetMessage GetMessageW override in Chrome code.
  69   std::string GetL10nMessage(const std::string& name) const;
  70
  71   // Get message from the given catalog with given key.
  72   static std::string GetL10nMessage(const std::string& name,
  73                                     const SubstitutionMap& dictionary);
  74
  75   // Number of messages in the catalog.
  76   // Used for unittesting only.
  77   size_t size() const { return dictionary_.size(); }
  78
  79   // Replaces all __MSG_message__ with values from the catalog.
  80   // Returns false if there is a message in text that's not defined in the
  81   // dictionary.
  82   bool ReplaceMessages(std::string* text, std::string* error) const;
  83   // Static version that accepts dictionary.
  84   static bool ReplaceMessagesWithExternalDictionary(
  85       const SubstitutionMap& dictionary, std::string* text, std::string* error);
  86
  87   // Replaces each occurance of variable placeholder with its value.
  88   // I.e. replaces __MSG_name__ with value from the catalog with the key "name".
  89   // Returns false if for a valid message/placeholder name there is no matching
  90   // replacement.
  91   // Public for easier unittesting.
  92   static bool ReplaceVariables(const SubstitutionMap& variables,
  93                                const std::string& var_begin,
  94                                const std::string& var_end,
  95                                std::string* message,
  96                                std::string* error);
  97
  98   // Allow only ascii 0-9, a-z, A-Z, and _ in the variable name.
  99   // Returns false if the input is empty or if it has illegal characters.
 100   static bool IsValidName(const std::string& name);
 101
 102   // Getter for dictionary_.
 103   const SubstitutionMap* dictionary() const { return &dictionary_; }
 104
 105   ~MessageBundle();
 106
 107  private:
 108   // Testing friend.
 109   friend class MessageBundleTest;
 110
 111   // Use Create to create MessageBundle instance.
 112   MessageBundle();
 113
 114   // Initializes the instance from the contents of vector of catalogs.
 115   // If the key is not present in more specific catalog we fall back to next one
 116   // (less specific).
 117   // Returns false on error.
 118   bool Init(const CatalogVector& locale_catalogs, std::string* error);
 119
 120   // Appends locale specific reserved messages to the dictionary.
 121   // Returns false if there was a conflict with user defined messages.
 122   bool AppendReservedMessagesForLocale(const std::string& application_locale,
 123                                        std::string* error);
 124
 125   // Helper methods that navigate JSON tree and return simplified message.
 126   // They replace all $PLACEHOLDERS$ with their value, and return just key/value
 127   // of the message.
 128   bool GetMessageValue(const std::string& key,
 129                        const base::DictionaryValue& catalog,
 130                        std::string* value,
 131                        std::string* error) const;
 132
 133   // Get all placeholders for a given message from JSON subtree.
 134   bool GetPlaceholders(const base::DictionaryValue& name_tree,
 135                        const std::string& name_key,
 136                        SubstitutionMap* placeholders,
 137                        std::string* error) const;
 138
 139   // For a given message, replaces all placeholders with their actual value.
 140   // Returns false if replacement failed (see ReplaceVariables).
 141   bool ReplacePlaceholders(const SubstitutionMap& placeholders,
 142                            std::string* message,
 143                            std::string* error) const;
 144
 145   // Holds all messages for application locale.
 146   SubstitutionMap dictionary_;
 147 };
 148
 149 ///////////////////////////////////////////////////////////////////////////////
 150 //
 151 // Renderer helper typedefs and functions.
 152 //
 153 ///////////////////////////////////////////////////////////////////////////////
 154
 155 // A map of message name to message.
 156 typedef std::map<std::string, std::string> L10nMessagesMap;
 157
 158 // A map of extension ID to l10n message map.
 159 typedef std::map<std::string, L10nMessagesMap > ExtensionToL10nMessagesMap;
 160
 161 // Returns the extension_id to messages map.
 162 ExtensionToL10nMessagesMap* GetExtensionToL10nMessagesMap();
 163
 164 // Returns message map that matches given extension_id, or NULL.
 165 L10nMessagesMap* GetL10nMessagesMap(const std::string& extension_id);
 166
 167 }  // namsepace extensions
 168
 169 #endif  // CHROME_COMMON_EXTENSIONS_MESSAGE_BUNDLE_H_